Abstract Attention-Deficit/Hyperactivity Disorder (ADHD) is one of the most commonly diagnosed mental health disorders in children, affecting approximately 5% of youth (APA, 2013). The long-term, developmental trajectory of ADHD suggests that these children continue to experience debilitating symptoms, as well as significant academic, social, and family difficulties into adulthood (Biederman et al., 2012). Given the impact of functional impairment associated with ADHD on the individual and society, it is imperative that effective treatment for ADHD be made available to as many affected youth as possible. In light of staggering mental health disparities for some of the fast growing ethnic minority groups in the United States, such as Latinos, it is particularly important to ensure effective treatment is available to these children who have not been well represented in treatment outcome studies examining parent management training for ADHD or other externalizing disorders (Flores & TCOPR, 2010; Miranda et al., 2005; U.S. Census Bureau, 2008).Thus, consistent with the goals of an R21, the current pilot study aims to close the existing gap in our knowledge about effective psychosocial treatments for Latino families by providing preliminary data regarding the acceptability and efficacy of a culturally-modified treatment and possible moderators that will support a future R01. Specifically, the current pilot study is the first step in a larger program of research aimed at definitively determining if culturally-modified treatment outperforms standard treatment when examining engagement and acceptability outcomes, as well as symptomatology and parental functioning, and if so, which treatment modifications are necessary and for whom. Participants will be 60 Latino children with ADHD and their parents. Families will receive either standard evidence-based treatment or culturally-modified treatment. The following aims will be explored: 1) does culturally-modified treatment result in better engagement and acceptability outcomes (i.e., parental attendance, retention, engagement, and satisfaction) than standard treatment and what is the strength of these effects, 2) does culturally-modified treatment result in improvements in ADHD symptomatology, as well as parental functioning (i.e., parenting stress and efficacy), does the modified treatment result in similar or greater improvements than standard treatment, and what is the strength of these effects, and 3) what possible moderators (i.e., socioeconomic status and behavioral and cognitive acculturation) may explain the relationship between treatment type (i.e., standard versus culturally-modified) and outcomes and what is the strength of these interactions.